Highly charged ion injector in the terminal of tandem accelerator

タンデム加速器の高電圧端子内高多価イオン入射器

松田 誠  ; 遊津 拓洋  ; 仲野谷 孝充  ; 沓掛 健一 ; 花島 進; 竹内 末広

Matsuda, Makoto; Asozu, Takuhiro; Nakanoya, Takamitsu; Kutsukake, Kenichi; Hanashima, Susumu; Takeuchi, Suehiro

Electron cyclotron resonance ion sources (ECRIS) are able to produce intense beams of highly charged positive ions. It is possible to increase beam intensity, beam energy and beam species by utilizing an ECRIS in the tandem accelerator. A 14.5 GHz all permanent magnet ECRIS has been installed in the high voltage terminal of the tandem accelerator at Japan Atomic Energy Agency at Tokai. The high voltage terminal is in a severe environment, i.e. it is filled with the pressurized insulation gas of 5.5 atm and itself is held at a voltage of 20 MV at maximum. The components of the injector have been confirmed to be pressure-resistant. A control system and circuits were designed to prevent damages from electrical discharges, and these electrical devices were heavily shielded. For the reason that ion pumps do not work for inert rare gases, a turbo molecular pump and a rotary pump were newly developed for the use in the high pressure gas. As a result of their developments, highly charged ions of Ne, Ar, Kr and Xe have been accelerated from the new injector. The rare gas ions have been available, and the intensities have been ten times higher than those before. Xe ion can be accelerated up to 400 MeV.